Note
The
time
required
to
construct
a
full
trace
that
is
averaged
to
the
desired
degree
is
approximately
the
same
when
using
either
the
averaging-bandwidth
or
the
video-averaging
technique
.
The
averaging-bandwidth
technique
completes
the
averaging
as
a
slow
sweep
is
taken,
whereas
the
video-averaging
technique
takes
many
sweeps
to
complete
the
average
.
Characteristics
of
the
signal
being
measured,
such
as
drift
and
duty
cycle
,
determine
which
technique
is
appropriate
.
Video
averaging
improves
the
display
of
low-level
signals
in
wide
bandwidths
by
averaging
the
signal
and
the
noise
.
As
the
receiver
takes
sweeps
,
you
can
watch
video
averaging
smooth
the
trace
.
1.
Set
the
receiver
to
a
known
state
by
pressing:
4
PRESET
5
4
BW
5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
IF
BW
AUTO
MAN
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30
4
kHz
5
2.
Connect
an
antenna
to
Input
2
of
the
receiver
and
position
a
low-level
signal
on
the
screen.
3.
Initiate
the
video
averaging
routine
by
pressing:
4
TRACE
5
N
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
More
1
of
3
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
VID
AVG
ON
OFF
ON
As
the
averaging
routine
smooths
the
trace
,
low-level
signals
become
more
visible
.
VID
AVG
100
appears
in
the
active
function
block.
The
number
represents
the
number
of
samples
(or
sweeps)
taken
to
complete
the
averaging
routine
.
4.
Set
the
number
of
samples
by
pressing:
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
VID
AVG
ON
OFF
ON
:
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25
4
(ENTER)
5
5.
Turn
video
averaging
o
and
on
again
by
pressing:
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
VID
AVG
ON
OFF
OFF
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
VID
AVG
ON
OFF
ON
The
number
of
samples
equals
the
number
of
sweeps
in
the
averaging
routine
.
6-28
Making
EMI
Diagnostic
Measurements